Project estimates

Gravel Calculator

Enter length, width, and depth to estimate gravel volume in cubic yards, see the approximate tonnage, and compare the raw quantity with the built-in compaction allowance.

Last reviewed May 17, 2026 by ToolSpilo Editorial Team.

Review method: Checked against the implemented volume equations and clarified that the 1.4 tons/cu yd conversion is a planning assumption rather than a supplier guarantee.

Calculator tool

How this calculator works

Use the explanation to understand the formula, assumptions, and practical limits behind the calculator result.

What Does the Gravel Calculator Measure?

The gravel calculator converts a project footprint into volume and then gives a planning weight estimate. That is useful for driveways, walkways, drainage beds, and landscaping areas where materials are commonly sold by either cubic yards or tons.

Formula Used

The calculator works in three steps:

Cubic feet=length×width×depth in inches12\text{Cubic feet} = \text{length} \times \text{width} \times \frac{\text{depth in inches}}{12}
Cubic yards=cubic feet27\text{Cubic yards} = \frac{\text{cubic feet}}{27}
Estimated tons=cubic yards×1.4\text{Estimated tons} = \text{cubic yards} \times 1.4

The last step uses the calculator's planning density of 1.4 tons per cubic yard. Actual weight changes with stone type, moisture, gradation, and supplier measurement, so the tonnage result is intentionally labeled as an estimate.

What the Outputs Mean

OutputMeaning
Cubic yards neededthe raw geometric volume
With 15% compactionthe calculator's buffered order quantity
Weight estimatevolume converted using the 1.4 tons/cu yd assumption
Cubic feetthe same volume before converting to yards

Worked Example

For a strip that is 30 ft long, 10 ft wide, and 4 in deep:

30×10×412=10030 \times 10 \times \dfrac{4}{12} = 100 cubic feet

10027=3.70\dfrac{100}{27} = 3.70 cubic yards

3.70×1.4=5.193.70 \times 1.4 = 5.19 estimated tons

With the calculator's 15% allowance, the buffered volume becomes 4.26 cubic yards.

What to Verify Before Ordering

The volume math is straightforward, but real orders depend on more than geometry. Confirm the final compacted depth, whether the site needs a separate base layer, the supplier's material density, the delivery minimum, and whether the surface is level or irregular.

If a quarry sells by weight, the supplier's own ton-per-yard figure should override the calculator assumption. If a project is sloped, rutted, or likely to settle, keep a practical buffer rather than ordering the exact raw number.

Frequently asked questions

Why does the calculator show both cubic yards and tons?

Because gravel is described by volume during planning but is often sold by weight. Cubic yards tell you how much space the material fills; tons estimate what that volume may weigh using the calculator's density assumption.

Why is there a 15% compaction allowance?

Loose material settles when it is spread and compacted. The extra quantity is a planning buffer so the installed depth does not fall short after placement. Use the supplier's or contractor's recommendation if they specify a different allowance.

What if my supplier says one cubic yard weighs something different?

Use the supplier's figure. Gravel weight changes with particle size, moisture, and stone type, so a local quarry ticket is more reliable than any generic online assumption.

Should I enter the finished depth or the loose depth?

Enter the depth you want after installation. The calculator separately shows a buffered quantity so you can plan for compaction without hiding that assumption inside the geometric volume.